1. Technical Field
The present invention relates in general to protecting an article, such as a circuit, during operation.
2. Description of the Related Art
Integrated circuit devices are often tested at test stations including a test handler and automated tester equipment (ATE). When testing begins, integrated circuit devices to be tested (each referred to a device under test (DUT)) are placed in a tray, tube, or other container in a loading area adjacent the ATE. Each DUT is then subjected to testing by the ATE one at a time or in multiples. To test a particular DUT, a pick-and-place mechanism of the test handler places the DUT on a test socket or contactor at a test head of the ATE. The ATE then tests the performance and/or reliability of the DUT utilizing one or more predetermined tests. After testing, the test handler places the tested DUT in one of multiple trays, or tubes in a sorting area based on the test results determined by the ATE. Thus, integrated circuit devices passing the test are segregated from those failing the test.
Because ATEs are not capable of testing all DUTs (e.g., DUTs having a higher performance than the ATE can accurately measure) and because the electromechanical interface of the ATE's interconnect assembly may adversely affect IC package test accuracy and reliability, a load board (sometimes referred to as a test interface unit) is often used to mechanically and electrically interface a DUT with the test head of the ATE. A load board usually includes a test socket or a contactor for holding a DUT on one side of the load board and testing support circuitry on the opposing side of the load board that connects to the test head of the ATE.
For some DUTs, testing is performed at one or more high and/or low temperatures to verify correct operation within a specified temperature range. When low temperature testing is performed, ice formation on the load board from ambient moisture may be a concern in that the ice can support leakage currents between points in the support circuitry on the load board, leading to improper operation or failure of the support circuitry on the load board and/or inaccurate test results.
To reduce ice formation, a “dry” gas, such as dry compressed air or nitrogen, is often utilized to purge the immediate environment of the support circuitry on the load board. However, many third party testing facilities, which are contracted by article manufacturers to perform testing, are not able to guarantee the moisture content of their compressed air sources and do not have an alternative dry gas available. Consequently, the present invention appreciates that it would be desirable to protect a circuit, such as a load board, during an operation, such as DUT testing.
U.S. Pat. No. 7,101,617 B2 to Cavallaro et al. discloses a removable protective coating for an electronic component that includes a thermoplastic film and a silicone layer on the underside of the film that contacts the electronic component. The silicon layer is formed by the application of heat or vacuum to silicone microcapsules coating the underside of the thermoplastic film. One disadvantage of the process disclosed by Cavallaro et al. is that the heat utilized to form the removable protective coating disclosed by Cavallaro et al. can damage the very electronic components to be protected. Moreover, the protective coating disclosed by Cavallaro et al. is not re-usable after removal from the electronic component.